SPRING HILL — The off-duty Tampa officer and off-duty Hernando deputy involved in the fatal shooting of a naked Hernando woman two months ago were justified in their actions, the State Attorney's Office has concluded.

Deputy Rocky Howard and Officer William Mechler only fired at 42-year-old Inga Marie Swanson after she pointed a firearm at Howard, advanced toward him and ignored repeated commands to drop the weapon, Assistant State Attorney Richard Ridgway wrote in a memo to State Attorney Brad King.

The memo, released Wednesday, shines more light on the bizarre circumstances surrounding the Oct. 20 shooting and gives more details regarding the events leading up to Swanson's death.

But it does not answer an obvious question: How did she get to that point in the first place?

The incident began at the home of Howard's in-laws at 9070 Orchard Way.

A friend of the in-laws, Eric Glass, was working on his truck, accompanied by his 5-year-old son.

While his son was sitting in the truck, he heard a woman yelling, "No, stop it," according to the memo.

Glass went to investigate and found Swanson next to the truck.

She opened the door and tried to get in, saying "I love you" repeatedly to the child, according to the memo.

Glass removed her from the truck, only then noticing she was completely naked.

As she walked away, she told him, "My daddy's going to kill you," the report said.

Howard and Mechler, who didn't see the incident, were told about it and went into the street to see what was going on. They saw Swanson walking down the street naked. At some point, she lay down.

Howard walked up to her to see if she needed help, and she started growling and making other noises.

Howard asked if she was okay. She said she was going to kill "that … Mexican." She then called Howard a name, got up and turned down a driveway.

At that point, Howard called the Hernando County Sheriff's Office's non-emergency line and asked that a deputy be sent to investigate. He said he thought the woman was either mentally ill or on drugs.

A short time later, Swanson returned and was carrying a weapon, the memo says.

She approached Mechler, Howard and a small group of others, including the child, who was still inside the truck.

"This is a heist," she said. "The kid is coming with me."

Howard and Mechler unholstered their weapons. They ordered her to drop her gun.

She didn't.

Continuing to walk toward them rapidly, she pointed the weapon at Howard.

They again ordered her to drop the gun, but she kept advancing toward Howard.

When she got within 20 feet, Howard and Mechler fired, striking Swanson.

She fell.

They gave her first aid and CPR until help arrived. She died at the scene.

Sheriff Al Nienhuis said Wednesday that the entire incident — from the time Swanson left to the time she returned with the gun — unfolded quickly and that on-duty deputies arrived within a minute or two after the shooting.

"I think the law enforcement officers were confronted with an extremely unusual situation," Nienhuis said. "I'm sure neither of them wanted this to be the outcome. But I don't think they logically could have done anything differently. It's unfortunate Miss Swanson escalated the situation before deputies could get there."

A specific timeline of the day's events was not available.

Swanson's gun, authorities later determined, was a .22-caliber, single-shot, break-open pistol. It was unloaded and inoperable because it was missing parts.

"There was, of course, no way either Deputy Howard or Officer Mechler could have known this," Ridgway wrote in his memo.

The gun belonged to her boyfriend, David Simpson, with whom she lived just a short distance down the road from where she was shot. Simpson said it was an antique firearm that had been mounted on the second floor of his home as a decoration.

Simpson gave authorities an account of Swanson's behavior that was similar to what he had told the Tampa Bay Times previously.

Swanson recently had begun acting agitated and was concerned about the Nov. 6 election. She was having mood swings. Sometimes she would growl and curse at her boyfriend, according to the memo.

The day before the shooting, Simpson suggested Swanson go to the hospital. She refused.

A toxicology report found marijuana in her system, but no other drugs.

Earlier the day she died, Swanson was seen by three people walking down a nearby road. They asked if she was okay, and she said, "Yeah, just a little confused," the report stated. She continued to walk.

A while later, the three men ran into her again while looking at a home one of them was considering buying.

She held a crucifix over her head.

"This is the Antichrist; let's wrap this up."

She then left.

They didn't call authorities.

The strange behavior doesn't mesh with the woman described by family and loved ones.

Swanson was compassionate and devoutly religious, frequently attending a Wednesday Bible study. She loved Christian radio and studied the Bible. She was modest and dressed conservatively, and could be extremely shy.

The events leading to her death took those around her by surprise and left them with a lot of questions.

Staff writer Tony Marrero contributed to this report. Danny Valentine can be reached at dvalentine@tampabay.com or (352) 848-1432.